Senior scientist Cindy Gilmour studies how anaerobic bacteria – found in places like the marsh soils above – transform mercury into methylmercury. Methylmercury poses a bigger problem than inorganic mercury because it bioaccumulates.

This January the Maryland Healthy Air Act goes into effect. It aims to significantly reduce emissions of air pollutants from the state’s coal-fired power plants. Mercury, like sulfur dioxides and nitrogen oxides, is one of the pollutants that can be released into the atmosphere during the combustion of coal and other fuels. The new law requires mercury emissions to be reduced by 80% now, and 90% by 2013, relative to a 2002 baseline. Maryland is just the latest to join a growing roster of states that have adopted tougher emissions regulations.

Cindy Gilmour will pay close attention to the impact of these new regulations on mercury levels in the Chesapeake Bay and its watersheds. Gilmour is a senior scientist at the Smithsonian Environmental Research Center (SERC), in Edgewater, Maryland. She took a few minutes to answer some questions about the science of mercury, why it’s of concern and what she does to monitor it in ecosystems.Click to continue »